Perhaps you should try some spelling variations:
nam thuoc » nam thu, nha thuoc, cay thuoc
sang tao » hang tai
tao khoi » tao hoi, thao khoa, lao khoa
than tai » thanh tai, toan tai, nhan tai
nam thuc » am thuc, nam thu, nam tu
han tai » hang tai, nhan tai, van tai
tu sach » thu sach, su sach, te sach
ky sang » ky nang, ky dang, ky tang
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky sang tao khoi. lieu va ((nam thuc) OR (nam thuoc)) xa ((han tai) or (than tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang tao khoi. lieu va ((nam thuc) OR (nam thuoc)) xa ((han tai) OR (than tai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky sang tao khoi. lieu va ((nam thuc) OR (nam thuoc)) xa ((han tai) or (than tai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang tao khoi. lieu va ((nam thuc) OR (nam thuoc)) xa ((han tai) or (than tai)) cua tre*.